The present invention relates to a spark chamber for a vacuum emission spectrometer with a housing, which accomodates an anode, as well as a sample table plate carried by the housing, on which a piece of material being inspected and making up the cathode is placed and which carries a spark centering plate.
In a vacuum emission spectrometer of this type the light emitted from a sample will be dispersed in its spectral colors and then measured. For this purpose it will be necessary to increase the energy level of the electrons orbiting around the nucleus in fixed orbits by temporarily supplying energy. This condition is instable, so that the electrons will fall back to their old level. These electron jumps will release energy, which will be radiated in the form of light rays.
Energy must be supplied in order to temporarily bring the electrons in an orbit of higher energy level. This is accomplished with sparks, which are produced between two electrodes. These sparks will tear out small particles from the piece of material being inspected, which then reach into the spark chamber. Consequently in the practice both the housing as well as the sample table plate, on which the sample being inspected is placed, are designed as ceramic parts. Because of permanent loads the service life of in particular the very expensive ceramic sample table plate is extremely short, so that this device cannot be operated very economically.
Consequently the task of the present invention shall be to provide a spark chamber for a vacuum emission spectrometer, of which the parts subject to wear are considerably more resistant to wear and therefore have a considerably longer service life than those of know devices, so that they can be operated more economically than these.